Because they are lightweight, do not corrode, and are easy to clean, unlike metal conveyor belts, plastic conveyor belts are used widely, especially in conveying food products. Modular plastic conveyor belts are made up of molded plastic modular links, or belt modules, that can be arranged side by side in rows of selectable width. A series of spaced apart link ends extending from each side of the modules include aligned apertures or holes to accommodate a pivot rod. The link ends along one end of a row of modules are interconnected with the link ends of an adjacent row. A pivot rod journaled in the aligned apertures of the side-by-side and end-to-end connected modules forms a hinge between adjacent rows. Rows of belt modules are connected together to form an endless conveyor belt capable of articulating about a drive sprocket.
In order to avoid having parts of the goods that are to be conveyed, such as food particles, from entering into the apertures or holes in the link ends and contacting the pivot rods, which can cause unsanitary conditions, modular flat top conveying belts are typically designed such that when they are rectilinear, they form a totally continuous, planar conveying surface. Typically, the link ends are narrow and in an assembled conveyor belt, the interconnected link ends completely enclose the pivot rods where they pass through the link ends. Having large portions of the pivot rods fully enclosed at all times by the link ends prevents thorough cleaning of both the pivot rods and their apertures or holes, unless the conveying belt is dismantled.
A conveyor belt constructed of modules designed such that the pivot rods and the link end apertures or holes can be cleaned without dismantling the belt is disclosed in U.S. Pat. No. 6,305,530 assigned to Habasit AG, which is the assignee of the present invention, and is incorporated herein by reference.
While the belt module shown in the '530 patent leaves open space on the side of the rod to allow access for cleaning fluid, the design reduces the link thickness above the oblong hole. This reduction in thickness may weaken the link and therefore limit the length of the oblong hole that is possible. Accordingly, there is a need for a design that provides open space on the side of the rod but does not significantly weaken the link.